const inputs = document.querySelectorAll(".input");

function focusFunction() {
    let parentNode = this.parentNode.parentNode;
    parentNode.classList.add('focus');
}

function blurFunction() {
    let parentNode = this.parentNode.parentNode;
    if (this.value == '') {
        parentNode.classList.remove('focus');
    }
}

inputs.forEach(input => {
    input.addEventListener('focus', focusFunction);
    input.addEventListener('blur', blurFunction);
});

